*2.4. Methodolgy*

The methodology used to develop and validate at a conceptual level the proposal of the Inspection Feature can be summarized as follows:

	- Tolerance information models used in CAT (Computer-Aided Tolerancing) applications, both for the interpretation models (such as vector equation model, variational surface model, kinematic model, degree of freedom (DOF) model, etc.) and for the representation models (such as surface graph model, technologically and topologically related surface (TTRS) models, category theory model, GeoSpelling model, ontology-based model, etc.). In particular, the concepts considered by the Geospelling language and the GPS standard are revisited.
	- Measurement processes and systems. More particularly, the ways in which the part can be situated (oriented and/or located) in relation to the geometries of the measurement resource are studied. Additionally, the alignment operations, either physical or by means of calculations (verification operator), that are performed during the verification process, are also analyzed.

In this work, only stages 3, 4 and 5 are covered due to space limitations, although a simple case study is presented so that the reader can see how the Inspection Feature can support the involved tasks in the inspection process plan specification. The rest of the stages are out of the scope of this work and they will be the object of future publications.

It should be noted that author's interest does not aim the development of an object-oriented application for inspection planning. Therefore, although UML notation has been used to show the concepts of the proposed model, the UML classes have not been detailed with their attributes and operations.
